Lathe dog



.1. M. WOOD LATHE DOG Filed DGC- 17. 1919 Patented Qct, 21, 1924.

UNITED STATES JOHN M. WOOD, OF DETROIT, MICHIGAN.

LATI-IE DOG.

Application led December 17, 1919.

T all whom t may concern.'

Be it known that I, JOHN M. VOOD, a citizen of the United States, and resident of Detroit, Wayne County, State of Michigan,

have invented certain new and useful Improvements in Lathe Dogs, Aof which the following is a specification.

This invention relates to lathe dogs.

One object of the invention is to provide a construction of this class in which the means for holding the clamping block against the work in a lathe are protected from being broken off by contact with moving parts.

Another object of the invention is to provide an improved form of clamping block permitting of the ready insertion of the block within the lathe dog frame.

With these objects and others in view, the invention is embodied in preferable form in the construction and arrangement hereinafter described and illustrated in the accompanying drawings, in which:

Figure 1 is a front view in elevation of a lathe dog showing my invention applied thereto;

Figure 2 is a section on the line 9.-2 of Figure 1 through the framel alone.

Figure 3 is a detail elevation of the clampl ing block, and

Figure 4, an edge view of said block.

Referring to the drawings, 10 indicates a lathe dog frame, a projecting portion of which is adapted to be engaged by a rotating part of the lathe such as a pin 11 pro-- jecting from the face plate or other circularly moving member of the mechanism for the purpose of rotating the lathe dog frame and the work clamped thereby. A piece of work, such for instance as a shaft, is indicated at 12. The frame is suitably shaped along a part of its inner surface to bear upon and engage the work` as at 13 and the work is pressed against the frame by means of a clamping block 14. In the particular construction herein shown this block is of a form which permits of convenient insertion within the body of the frame and secure engagement therewith in such a manner as to prevent lateral displacement of the block. To this end the block has a curved inner bear- Serial No. 345,524.

ing face 15 adapted to bear upon the work 12 and is provided in each side border thereof with a recess 16, which recesses are adapted to slip over opposite lugs 17 projecting from the interior opposite faces of the fra-me of the lathe dog. Also projecting centrally from these inner faces of the frame below the lugs 17 are ribs 18, the upper ends of which are spaced from the lugs 17 a sutlicient distance to permit the block Mato be passed freely above the upper ends of the ribs when it is inserted within the frame past the lugs 17. The block is provided at each side with interior slots 19 extending from the side edges inwardly for'some distance and forming` locking slots or kerfs which are adapted to engage the lugs 17 and the ribs 18 so as to key the block firmly within the frame against lateral movement. The block is inserted in the frame by slipping the recessed portions thereof past the lugs 17 and causing the slots of the block to register with these lugs and then dropping the block into place, in which position the lugs and ribs will serve as keys to retain the block.

The block is clamped against the work 12 by means of a pressure member, such as a setscrew 20, which is provided with a polygonal nut or head 21 projecting from the set screw on the inner side of the frame which has a threaded socket adapted to receive the set screw. The set screw is inserted and removed when the block is in its lower position on the ribs 18 with no work in the frame. In this construction the head of the screw bears directly against the block and the screw may be turned to clamp or release the block and the work by means of e a wrench inserted into the hollow frame so as to engage they nut. With this arrangement the nut or head of the set screw is protected by the surrounding frame and hence the liability of breaking the head by contact with movable parts is avoided.

The ypart of the fra-me in which the threaded socket is formed constitutes an additional tail 22 for the dog and this tail is adapted to bear against a pin 23 also projecting from the face plate on the same side as the pin 11, against which the lower l tail of the dog is adapted to project, wherevented from turning .over after the ont has been completed land the tail has passed above the center line of the dog.

Having thus described my invention, what I Aclaim and desire to secure by Letters W Patent is:

In a lathe dog, a frame therefor including radial teils at the upper and lower ends of the dog in combination with suitable engaging ineens adapted tox beer against said teils Von the saine sides thereof above and below `the center of the dog whereby the dogl Y AJol-nv M. 'woon 

